Self-sealing container



April 6, 1948. L'. MCLAUGHLIN 2,439,366

SELF-SEALING CONTAINER Filed Feb. 24, 1941 Patented Apr. 6, 19482,439,366 SELF-SEALING CONTAINER Leone McLaughlin,

Akron, Ohio, assignor to Wingi'oot Corporation, Akron, Ohio, acorporation of Delaware Application February 24, 1941, Serial No.380,259 4 Claims. (Cl. 1543.5)

This invention relates to improvements in the i construction ofcontainers adapted to hold liquids and, more particularly, toself-sealing fuel tanks for airplanes and the like.

In the construction of fuel airplanes, it is impossible to make thetanks sufficiently strong to resist the penetration of bullets due tothe necessity for avoiding any increase in weight of the plane, as faras possible;` Therefore, these fuel tanks have been constructed so as topermit the projectile to pass through the `walls of the tank, and thenseal the hole after puncture. This is effected by incorporating in thewalls of the tank certain self-sealing materials, such as rubber, whichare soft enough to flow or which swell upon contact with the gasoline oroil in the tank, the effect in either case being to close the holepromptly and prevent the escape. of the fluid. These self-sealingmaterials necessarily have little strength, since they mu'st be soft andcapable of swelling in the gasoline or other hydrocarbon contained inthe tank and it is, therefore.

`necessary to` support the self-sealing material with layers or plies ofstronger materials.

In the selection of materials having the desired strength, it isneedful, not only that the liner in which they are incorporated have therequisite strength in the unpunctured condition, but also that it retainits strengh in large partafter being pierced a number of times inservice. The severest test of a. tank takes place at the point of exitof a bullet or other projectile since the penetration 'at the point ofentrance and the-passage through the liquid in the tank often cause thebullet te yew rvr-tumble before it exits. As th-n result, the bullet mayrip through the wall of the tank, as it leaves, broadside or at anangle.- This causes a relativelylarge jagged hole and may remove thesupport for the self-sealing layer at that point. The weight of thefluid in the tank and the surges set up by the passage of the bullettherethrough may then force the soft material into the opening andmaintain lthe bullet hole in a distended condition, thus preventingsailing.

tanks for military v uncured rubber or partially cured 4 where thebullet rips through the fabric crosswise, since then a large number ofthreads are cut. The result is that the bullet hole may still remaindistended in this now unsupported region and fuel will be lost, causingthe return of the plane to its base or a forced landing.

In order to overcome this defect of liners incorporating cross-wovenfabric, the present in vention contemplates the use of cord fabric inplace o f lsuch crosswoven fabric. Cord fabric.

as is well known, consists essentially of warp threads or cords only, noweft threads being present or, if present, being few and weak. Such weftthreads, if present, are intended only to hold the cords together untilthe fabric has been frictioned lor otherwise treated with an adhesivematerial which takes over the function of holding the cords in place.I'he function of the weft threads having been places along their lengthin order that they may not crimp the cords or This is particularly trueof tank linings made.

up of `a layer of partially cured rubber or like .hold liquids.

chafe the same at their points of contact. Hence, for the purposes ofthis invention, a weftless fabric `and a broken-weft fabric areconsidered to be equivalents since in each case the weft threads do notfunction in the finished article.

One obect of the invention is to provide an lmproved liner forself-sealing tanks adapted to Another object of the invention is toprovide a liner for airplane fuel tanks of improved self-sealingcharacteristics. Other objects will in part be obvious andwill in partbe pointed out hereinafter. I

The invention will be described in connection with the accompanyingdrawings, wherein one form of the invention has been shown merely by wayof illustration and wherein:

Figline 1 is a plan view of a liner embodying the invention withportions of the various plies and layers broken away. and

made up of several layers and plies of material.

completed, they are often broken at a number of 'stantially unsupportedat 2,4easee a layer of semi-cured rubber i, approximately v IA" inthickness. Another this time with the cords running horizontally andhence at an intermediate angle to the cords in each of the plies 3 and4. separates the sealing layer 5 from another layer of partially curedrubber 1. This in turn is covered with a plyA 8 of fabric which has beencoated with neoprene (polymerized chloro butadiene) or othersynthetf icrubber resistant to gasoline and hydrocarbons generally.

When a bullet pierces a lining having the foregoing structure, it may bepositioned with its longitudinal axis at right angles to the cords ofply 3, for example,l in which event it will break a maximum number ofcords in this ply. Were this the only reinforcement for the sealinglayer 5 or were additional plies disposed with their cords runningparallel to those in ply 3, it will be Y obvious that a large hole wouldbe left in the liner and the soft rubber layer 5 would be subthis point.This condition is prevented, however, by the disposition 'of the plies 4and 6. Since the cords in ply l are disposed at cross angles to thecords in ply 3, a bullet cutting the maximum number of cords in ply 3will cut a minimum number of cords in ply 4 since the bulletslongitudinal axis will be parallel to the cords in this second ply.Likewise, a bullet in a position to break the largest number of cords inplies 3 and l taken together, will break a minimum number of cords inply 6. As a consequence. Ione ply or the other will suffer a minimumamount'of breakage and will continue to function as a support for one orthe other of the sealing layers i and 1. Sealing of the bullet hole plyof cord fabric 6,'

at any point throughout the thickness of the liner will, of course, stopthe escape of fluid from the tank.

While the invention has been described in connection with one specificembodiment thereof, it .will be understood that various combinations offabric plies and sealing layers may be effected, all without departingfrom the scope of the invention. Thus, in its simplest form, theimproved liner may consist of one layer of not more than are few andweak, or that in which the weft threads have been broken, leaving onlythe warp threads in functioning condition. By omitting the weft threads,it is possible to have more warp threads in a given space since theyAmay be'placed closelyl parallel to each other in the fabric and thusgreater strength is secured. Also, omission of the weft threads somewhatdecreases the thick'- ness of the ply and hence the thickness of theliner, space and weight being a consideration in all airplaneconstruction. The fabricvplieswill be placed with the cords of each atangles to the cords of the others, preferably at cross angles. Wheremore than two plies arepresent, the maximum possible angles between thecords of each ply and those of the others will be maintained. The fabricplies may be placed on either side of the sealing layer or two plies maybe bonded topartially cured rubber, by which is intended to includeuncompounded uncured rubber as well tion, it will ordinarily bedesirable to face the liner on the inside with a ply of neoprene-coatedfabric or fabric coated with some other material which is resistant toattack by the gasoline, since otherwise rubber would be dissolved andVwould contaminate the fuel or lubricating oil. This ply may becross-woven if desired. 0n the outer side of the liner, additionalstrength-giving materials may be present, such as plywood or Plioform,cyclized rubber, serving to maintain the contour of the exible hner. Thewhole may be enclosed in a metal casing or, preferably, will be placedin the wing of an airplane where the walls of the wing and bulkheadswill serve to support the tank.

While there has been described above one prefered vembodiment of theinvention, it will be apparent that the same may be modified in variousrespects, as indicated, or in any other feasible manner. It is intended,then, that the patent shall cover, by suitable expression in theappended claims, all features of patentable novelty residing in theinvention. v

I claim:

1. A liner for self-sealing containers adapted to hold liquidhydrocarbons comprising a layer of partially cured rubber, two plies ofweftless or broken-weft fabric with the warp threads of` each at crossangles to those of the other bonded together and to one side of saidrubber layer, a third ply of weftless or broken-weft fabric bonded tothe other side of said rubber layer with the warp threads at anintermediate angle to the warp threads of the other two plies and a plyof polymerized chlorobutadiene coated fabric bonded to said third fabricply.

2. A liner for self-sealing containers adapted to hold liquidhydrocarbons comprising at least two layers of rubber capable ofswelling in a hydrocarbon and at least two plies of weftless orbrowen-weft fabric interleaved with said rubber layers and bondedthereto with the warp threads of each ply at an angle to those in eachof the said liner.

4. A compact liner for self-sealing containers adapted to holdhydrocarbon liquids consisting of not more than several layers ofhydrocarbon-sensitive rubber adapted on contact with a liquid'hydrocarbon to quickly seal a rupture of the liner, a plurality offabric plies in supporting relation with a sealing layer, at least oneof said plies being disposed face to face with said sealing layer andanother said ply being face to face with one of said sealingv layer andsaid first. ply, said respective plies comprising weftless orbroken-weft cord fabric arranged with the cords of the respective pliesextendingat a substantial so that less cords will orin one ply than inanother' ply when the liner is ruptured. and an inner facing on theliner of hydrocarbon resistant material adapted to protect thehydrocarbon-sensitive layer against exposure to a hydrocarbon untilrupture occurs.

LEONE McLAUGHLIN.

REFERENCES The following references are of record in the patented le ofthis patent:

angle to each other dinarily be severed Number 6 UNITED `STA'I'ESPATENTS Name Date Landis Oct. 12, 1915 Denman Jan. 2. 1917 Ericsson June14, 1921` Privett May 1, 1923 Hopkinson Feb. 28, 1928 Gray et al Dec.21, 1937 FOREIGN PATENTS Country Date Number 301.089

Great Britain Sept. 26, 1929

